Application Note 13

PIEXX SO2Rxlat DXD Accessory

Using the DXD with a USB Port

Background:

The Top Ten Devices DX Doubler (DXD) is a Single Op 2 Radio controller designed to be controlled by signals appearing on the LPT port of a computer running compatible software.  Few modern computers come equipped with an LPT port, so a solution is needed to allow the DXD to be used with these computers.  Commonly available USB to LPT converters only work with printers, and can not be used for DXD control.

USB to LPT Converter:

PIEXX Co. has just announced a product called the SO2Rxlat, so named because it will translate ("xlat") commands sent to USB-connected devices to an LPT-style connector, which can be routed to the input of the DXD, a Single Op 2 Radio ("SO2R") controller.  Read about the DXD here .

Details of the SO2Rxlat can be found here.  It should be noted that in addition to providing USB control of the DXD, the SO2Rxlat also:

• Has a serial port for radio control
• Can provide Band Data for use with a Top Ten Band Decoder

Using the SO2Rxlat with the DXD:

First, install and test the SO2Rxlat USB drivers per the PIEXX instructions.

The SO2Rxlat comes in a small case with a DB25F connector.  Connection to the DXD can be made either of two ways:

1. A gender changer - Gender changers provide a convenient way to "bolt up" the DXD and SO2Rxlat.  The photo below shows this configuration:
   
   
   
   Note that the machine screws on the gender changer are engaged with the jack screws on the DB connectors on both the DXD and SO2Rxlat.  This provides a secure connection.  However, the SO2Rxlat is "cantilevered" out a few inches from the rear of the DXD, with its bottom about 1/4" above the table.  A spacer of some sort can be attached to the bottom of the SO2Rxlat to provide support and take the stress off the connectors.
   
2. Cable connection - A common 25-wire straight through computer cable can be used to connect the two devices, as shown here:
   
   
   
   
   The advantage of this is that it allows the SO2Rxlat to be located away from the DXD, thus providing more flexibility in locating/arranging the DXD, due to a shallower profile than if the gender changer had been used.  The cable shown was purchased via mail order from ComputerGate.   The USB cable shown in the photo above is provided by PIEXX.

DXD Functionality with SO2Rxlat

The SO2Rxlat emulates the LPT port control signals for:

• Radio 1 vs Radio 2 select
• Computer generated CW and PTT signals
• K8CC's "NA-style" headphone audio controls, such as Stereo.  (You must configure the DXD for NA if you wish to use these capabilities, provided your software supports them.)
• Band Data - Many software logging applications will send a four-bit binary word to the LPT port to be used with external decoders for automatic antenna selection.  Read about this here.  The SO2Rxlat properly provides this data on its output connector.  The four lines are "passed through" the DXD and appear on the DB9 connector on the rear panel adjacent to the "LPT Port" connector.

None of the SO2Rxlat configurations need to be adjusted for DXD compatability.  Just hook it up and operate the DXD as if were connected to a real LPT port.

Software Compatibility

The contest logging programs that are known to support the SO2Rxlat include:

• N1MM Logger
• Wintest
• WriteLog (beta testing)

Others will no doubt add support in due course.

Contact Information

Any questions about the SO2Rxlat should be directed to PIEXX at their web site.

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